Suppliers (manufacturing facilities) who would like to join the ZDHC Gateway do not have to pay an access fee. Account registration is free.
To make full use of the ZDHC Gateway by sharing performance data with connected Brands, some additional costs need to be considered: 

Wastewater Test and ZDHC ClearStream Reports

Suppliers can conduct wastewater testing according to the ZDHC Wastewater Guidelines. This is done by ZDHC Approved Wastewater Laboratories, and the costs for the testing must be discussed with the Wastewater Laboratories directly. Find more information on ZDHC Wastewater Guidelines here.
In order to upload the wastewater test report and generate the ZDHC ClearStream Report in the ZDHC Gateway, an annual wastewater reporting subscription fee needs to be paid within the ZDHC Gateway. This fee is 250€ per subscription year. This fee can either be paid by the supplier or directly by the involved Wastewater Laboratory on behalf of the supplier on the ZDHC Gateway. Read more here about how Wastewater Laboratories can pay the wastewater subscription fee on behalf of the supplier. 

ZDHC Performance InCheck Report

To be able to generate a ZDHC Performance InCheck Report that demonstrates the ZDHC conformance of a supplier’s chemical inventory, the supplier must contact a ZDHC Approved Solution Provider. The costs for Performance InCheck Report subscription fees vary per Solution Provider and are to be discussed with them directly. Find more information on the ZDHC Performance InCheck Report here.